Current Electricity — Flashcards

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Ohm's Law states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) across its ends, provided the physical conditions like temperature and pressu…

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Given: V = 10 V, I = 2 A Using Ohm’s Law: R = V / I Step 1: R = 10 V / 2 A = 5 Ω Answer: 5 Ω…

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When the switch is turned on, an electric field is established almost instantly throughout the circuit. This field exerts a force on free electrons in the conductor, causing them to drift and produce …

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Electric current is the rate of flow of electric charge through a cross-sectional area of a conductor. Mathematically, I = Δq / Δt, where Δq is the net charge passing through the area in time Δt. The …

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Given: Number of electrons = 3 × 10¹⁸, t = 2 s Charge of one electron = 1.6 × 10⁻¹⁹ C Total charge: q = (3 × 10¹⁸) × (1.6 × 10⁻¹⁹) = 0.48 C Current: I = q / t = 0.48 C / 2 s = 0.24 A Answer: 0.24 A…

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Resistivity (ρ) is an intrinsic property of a material that measures how strongly it opposes the flow of electric current. It depends only on the nature and temperature of the material, not on its dim…

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Given: L = 2 m, A = 2 × 10⁻⁶ m², ρ = 1.7 × 10⁻⁸ Ω·m Formula: R = ρL / A Step 1: R = (1.7 × 10⁻⁸) × (2) / (2 × 10⁻⁶) Step 2: R = (3.4 × 10⁻⁸) / (2 × 10⁻⁶) = 1.7 × 10⁻² Ω Answer: 0.017 Ω…

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Let wire 1: L₁ = L, r₁ = 2r → A₁ = π(2r)² = 4πr² Wire 2: L₂ = 2L, r₂ = r → A₂ = πr² R ∝ L / A So, R₁/R₂ = (L₁/L₂) × (A₂/A₁) = (1/2) × (πr² / 4πr²) = (1/2) × (1/4) = 1/8 Therefore, R₁ : R₂ = 1 : 8…